The recommended way to log from spiders is by using the Spider
log() method, which already populates the
spider argument of the scrapy.log.msg() function. The other arguments
are passed directly to the msg() function.

logstdout (boolean) – if True, all standard output (and error) of your
application will be logged instead. For example if you “print ‘hello’”
it will appear in the Scrapy log. If ommited, the LOG_STDOUT
setting will be used.